Establishment of a Rat Model of Ulcerative Colitis by Immunological Sensitization Combined with Local Acetic Acid Irritation / 中国实验动物学报

ABSTRACT

Objective To establish a rat model of ulcerative colitis by immunological sensitization combined with local acetic acid irritation.Methods Thirty healthy 2-3-month-old Wistar rats were randomly divided into 3 groupsnormal control group,model group and SASP-treated model group(n=10 rats per group).The ulcerative colitis in the model group and positive group was developed by immunological sensitization with rabbit colon mucosal proteins and local irritation with 5%acetic acid.The rats of the model and positive groups were fed with sulfasalazine,and rats of the control group fed with normal saline.The rats of positive control group were treated with sulfasalazine.Two weeks later,all rats were killed and colon mucosal and blood samples were collected.The concentrations of NO,NOS,MDA,SOD and GSH-Px in the colonic mucosal homogenate were measured by biochemistry,the contents of IL-4 and TNF-α were measured by RIA,and the serum concentration of IFN-γ was measured by ELISA.Results Compared with the normal control group,the concentration of MDA,NO,NOS in the colonic mucosa was increased,and SOD and GSH-Px levels significantly decreased in the model group.Compared with the model group,the concentrations of MDA,NO,and NOS in the colonic mucosal tissue were decreased,and the levels of SOD and GSH-Px decreased in the SASP-treated model group.The contents of IL-4 in the serum and colonic mucosal homogenate of model group were significantly lower, and the contents of TNF-α in the serum and colonic mucosal homogenate were significantly increased than those of the normal control group. The IL-4 levels in the serum and colonic mucosal homogenate was increased, and that of TNF and IFN-γ significantly decreased in the SASP-treated model group, compared with those of the normal control group.Conclusion The rat model of ulcerative colitis established by immunological sensitization combined with local acetic acid irritation, as described in the present study, can better simulate the characteristic chronic alterations in human ulcerative colitis,and may better serve studies and evaluation of treatment of this disease.